Sexually Transmitted Disease (STD)
A sexually transmitted disease (STD), also known as a sexually transmitted infection (STI), or venereal disease (VD), is an illness that has a significant probability of transmission between humans by means of human sexual behavior, including vaginal intercourse, oral sex, and anal sex. While in the past, these illnesses have mostly been referred to as STDs or VD, in recent years the term sexually transmitted infections (STIs) has been preferred, as it has a broader range of meaning; a person may be infected, and may potentially infect others, without showing signs of disease. Some STIs can also be transmitted via the use of IV drug needles after its use by an infected person, as well as through childbirth or breast-feeding. Sexually transmitted infections are as follows:
Bacterial
Fungal
Viral
Parasites
Protozoal
The male reproductive organ of flower is called:
(a) Stamen
(b) Carpel
(c) Petals
(d) Sepals
(e) None of these
Answer: (a)
Which one of the following flower is bisexual?
(a) Rose
(b) Jasmine
(c) Hibiscus
(d) Lotus
(e) None of these
Answer (c)
Which one of the following animals shows external fertilization?
(a) Birds
(b) Toads
(c) Reptiles
(d) Goat
(e) None of these
Answer (b)
Which one of the following is a male sex chromosomes?
(a) XX
(b) YY
(c) XY
(d) All of these
(e) None of these
Answer: (c)
Reproductive Health
Birth control is a term for several techniques and methods used to prevent fertilization or to interrupt pregnancy at various stages. Birth control techniques and methods include contraception , contragestion and abortion.
Contraception includes barrier methods, such as condoms or diaphragm, hormonal contraception, also known as oral contraception, and injectable contraceptives. Contragestives, also known as post-coital birth control, include intrauterine devices and what is known as the morning after pill.
The most common methods of hormonal contraception include the combined oral contraceptive pill and the minipill. Hormonal emergency contraception can be both contraceptive and contragestive.
Sterilization
Surgical sterilization is available in the form of tubal ligation for women and vasectomy for men. Although sterilization is considered a permanent procedure due to the uncertainty of reversal possibility, it is possible to attempt a tubal reversal to reconnect the Fallopian tubes in females or a vasectomy reversal to reconnect the vasa deferentia in males. The rate of success depends on the type of sterilization that was originally performed and damage done to the tubes as well as the patient's age.
Vasectomy
A vasectomy is a minor surgical procedure for male sterilization and birth control. During the procedure, the vasa deferentia of a man are severed/and then tied in a manner which prevents sperm from entering into the seminal stream. Vasectomy should not be confused with the surgical removal of the testicles. 
Sexual Reproduction
In this mode of reproduction both male and female are involved. The female egg cell fuse with the male egg cell to form zygote, which then develops into the new individual. These egg cells are also called gametes. When the male and female gametes fuses with each other, it forms zygote, which starts growing into new individual.
Flowering Plants
Flowering plants are the dominant plant form on land and they reproduce by sexual and asexual means. Often their most distinguishing feature is their reproductive organs/ commonly called flowers. The anther produces male gametophytes, the sperm is produced in pollen grains, which is attached to the stigma on top of a carpel, in which the female gametophytes are located. After the pollen tube grows through the carpel's style, the sex cell nuclei from the pollen grain migrate into the ovule to fertilize the egg cell and endosperm nuclei within the female gametophyte, in a process termed double fertilization. The resulting zygote develops into an embryo, while the triploid endosperm i.e. one sperm cell plus two female cells and female tissues of the ovule give rise to the surrounding tissues in the developing seed. The ovary, which produced the female gametophyte, grows into a fruit, which surrounds the seed. Plants may either self-pollinate or cross-pollinate. No flowering plants like ferns, moss and liverworts use other means of sexual reproduction.
Sexual Reproduction in Animals
Male
The male reproductive system contains two main divisions: the penis, and the testicles, where the sperm are produced. In humans, both of these organs are outside the abdominal cavity, but they can be primarily housed within the abdomen in other animals, for instance, in dogs, the penis is internal except when mating. Having the testicles outside the abdomen best facilitates temperature regulation of the sperm, which require specific temperatures to survive. Sperm are the smaller of the two gametes and are generally very short- lived, requiring males to produce them continuously from the time of sexual maturity until death. Prior to ejaculation the produced sperm are stored in the epididymis. The sperm cells are motile and they swim using tail-like flagella to propel themselves towards the ovum. The sperm follows temperature gradients and chemical gradients to locate the ovum.
Female
The female reproductive system likewise contains two main divisions: the vagina and uterus, which act as the receptacle for the sperm, and the ovaries, which produce the female's ova. All of these parts are always internal. The vagina is attached to the uterus through the cervix, while the uterus is attached more... 
Introduction
We know that every living organism have a certain life span and it dies after sometime. So new organisms have to be produced in place of the dead organisms. Thus, the production of new organisms from preexisting organisms of the same species is known as reproduction. The reproduction ensures the continuity of life on earth. It gives rise to more organisms with same basic characteristics as their parents. Organisms look similar, because their body designs are similar. If the designs are to be similar, the blue prints for these designs should be similar. Thus, the reproduction at its most basic level will involve making copies of the blueprints of body designs. The DNA in the cell nucleus is the information source for making proteins. If the information is changed, different proteins will be made which eventually lead to altered body designs. Therefore, a basic events in reproduction is the creation of a DNA copy.
Cells use the chemical reactions to build copies of their DNA. They create two copies of the DNA in a reproducing cell which need to be separated from each other. However, keeping one copy of DNA in the original cell and simply pushing the other one out would not work, because the copy pushed out would not have any organized cellular structure for maintaining life processes. Therefore, DNA copying is accompanied by the creation of an additional cellular apparatus. The DNA copies separate, each with its own cellular apparatus, effectively, a cell divides to give rise to two cells.
Types of Reproductions
There are two modes of reproduction in living organisms such as asexual and sexual reproduction. In case of asexual reproduction, only one organism is involved. Whereas in sexual reproduction both the organism, male and female are involved. In asexual reproduction, no sex cell are involved. For example, binary fission in amoeba, budding in Hydra and many more. Whereas in sexual reproductions, the sex cell of one parent fuses with the sex cell of the other parent to form a new cell called 'zygote'. The zygote grows and develops to form a new organism.
Asexual Reproduction
In a sexual reproduction, certain body cells of the parent organism undergo repeated miotic cell divisions to form two new organisms of the same kind. There are different methods of asexual reproduction, which are explain as below:
Binary Fission
In this methods single organism divides to form two new organisms. For example, the organisms like amoeba, paramecium, bacteria reproduce by this method.
3. Cytoplasm divides 4. Two daughter more... 
Coordination in Animals
The coordination in animals is brought by hormones and nervous system. The hormones are the chemical substance which controls the various growth activities in the animals and plants. The hormones are secreted by the endocrine system in the animals. The endocrine system consists of ductless glands which generates the hormones. The various endocrine glands in human being are as follows:
Pituitary Gland
This gland is attached to the central part of the brain and secrets the pituitary hormones also called growth hormones. It controls the functioning of other endocrine glands. It also regulates the growth and development of body. If excess of hormones is stored then it cause gigantism and if insufficient of hormones is secreted, it cause dwarfism.
Pineal Gland
It is a small gland attached to the dorsal part of the brain. It controls the time mechanism of the organism, which regulates the sleeping of man.
Thymus Gland
This gland is found in small babies which produce WBC to protect babies from diseases and disappears with the age.
Thyroid Gland
This gland is found behind larynx and secrets thyroxine hormones which contains iodine. It controls the metabolism of carbohydrates, fats and proteins. Excessive secretion of this hormones cause hyperthyroidism and insufficient secretion cause goiter.
Parathyroid Gland
This gland is inside the thyroid gland and secrets parathormone which increase the level of calcium in blood.
Adrenal Gland
It is located on kidney and secrets the hormones called adrenaline. When a person is fighting or running or get frightened this hormones is secreted in large amount.
Testis
It secrets male sex hormones called testrone which begins at the onset of puberty. It helps in development of sperm, beard, moustache, hard voice etc.
Ovaries
It secrets female sex hormones called oestrogen and progesterone. It produces egg cells in female. It leads to fertilization in female and production of baby in female.
Which tropism is responsible for the movement of plants in response to the chemicals?
(a) Phototropism
(b) Geotropism
(c) Chemotropism
(d) Hydrotropism
(e) None of these
Answer: (c)
Which plant hormones is responsible for elongation in plants?
(a) Auxins
(b) Cytokinins
(c) Gibberellins
(d) Abscisic Acid more... 
Coordination in Plants
Unlike animals, plants do not have nervous system for coordination and control of body activities. They does not have muscles for these activities. But despite all this, the plants responds to the stimulus and coordinates their function. There are infact specialized tissue in the plants for these activities. These specialized tissue is called xylem and phloem. Apart from these, the other substances, which helps in coordination are hormones. The different hormones found in plants are Auxin, gibberellins, cytokinins and abscisic acid. Auxins are founded in the apical meristem of the root tips and shoot tips. When the light falls on the shoot tips the auxin hormones get excited and speeds up the cell division at the shoot tips and leads to the elongation of shoots of the plants.
The second hormone, gibberellins helps in elongation of stem and germination of seeds and flower. The third hormones, cytokinins promotes cell division and helps in breaking dormancy of seeds of the plants. The fourth hormones, abscisic acid inhibits the growth of the plants. It promotes the falling of seeds and fruits form the plants. 
Human Brain
One of the most important part of the human body is the human brain. All the thinking and memory work is done by the brain. It is divided into three parts fore brain, mid brain and hind brain. The fore brain is the main thinking part of the brain. It receives sensory impulses from various receptors. Different areas of fore brain are specialized for hearing, smell, sight and so on. Many of the involuntary actions such as watering of mouth when we see some delicious food, heart beat etc are controlled by the mid brain and hind brain. The other involuntary actions such as blood pressure, salivation, vomiting etc are controlled by the medulla of the hind brain. The activities such as walking in straight line, riding a bicycle, picking up pens etc are controlled by cerebellum of hind brain.
Tropic Movement
The movement of organism towards or away from the stimulus is called tropic movement. If the movement is towards the stimulus then it is called positive stimulus and if it is away from the stimulus then it is called negative stimulus. The various types of tropic movements are:
Phototropism
The response of organism towards the light is called phototropism. For example, a money plant kept in a pot in a room grows more towards the direction from which the light is coming, as compared to the other direction.
Geotropism
Response of organism towards the gravity is called geotropism. The root of the plant grows deep into the earth is an example of geotropism.
Hydrotropism
The growth of plants parts towards the water is called hydrotropism.
Chemotropism
The growth of plant parts towards the chemicals is called chemotropism. For example roots, of plants grows more towards the chemical fertilizers.
Thigmotropism
The response of organism towards the touch or contacts is called thigmotropism. For example, touch me not plant.
Reflex Action
A reflex action, also known as a reflex, is an involuntary and nearly instantaneous movement in response to a stimulus. A true reflex is a behavior, which is mediated via the reflex arc. In animals, reaction time to visual stimuli is typically 150 to 300 milliseconds
A reflex arc is a neural pathway that controls an action reflex. In higher animals, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord. This characteristic allows reflex actions to occur relatively quickly by activating spinal motor neurons, without the delay of routing signals through the brain. Although the brain receives sensory input while the reflex action occurs.
There are two types of reflex arc - autonomic reflex arc affecting inner organs and somatic reflex arc affecting muscles. When a reflex arc consists of only two neurons in an animal i.e. one sensory neuron, and one motor neuron. It is defined as monosynaptic. Monosynaptic refers to the presence of a single chemical synapse. In the case of peripheral muscle reflexes, brief stimulation to the muscle spindle results in contraction of the agonist or effector muscle. By contrast, in polysynaptic reflex pathways, one or more interneurons connect afferent (sensory) and efferent (motor) signals. 
Introduction
In the previous chapter we have studied about the various activities involved in the maintenance of life process. In this chapter, we will discuss "how our body controls these various activities"?. How do we coordinate and response to the external stimulus? There must be a system which provides the control and coordination activities in the multicellular organisms.
The ability of the organism to detect changes and make appropriate response is called sensitivity. Anything to which an organism responds and reacts is called a stimulus. Animals response to the stimulus either by moving towards it, or by moving away from it. Response and coordination in animals involve the sense organs, nervous system and hormones.
Nervous System
The nervous system is an organ system containing a network of specialized cells, called neurons. It coordinate the actions of an animal and transmit signals between different parts of its body. In most animals the nervous system consists of two parts, central and peripheral. The central nervous system of vertebrates contains the brain, spinal cord, and retina. The peripheral nervous system consists of sensory neurons, clusters of neurons called ganglia, and nerves connecting them to each other and to the central nervous system. These regions are all interconnected by means of complex neural pathways.
The enteric nervous system, a subsystem of the peripheral nervous system, has the capacity, even when severed from the rest of the nervous system through its primary connection by the vagus nerve, to function independently in controlling the gastrointestinal system.
Neurons send signals to other cells as electrochemical waves travelling along thin fibers called axons. This causes chemicals called neurotransmitters to be released at junctions, called synapses. A cell that receives a synaptic signal may be excited, inhibited, or otherwise modulated.
Sensory neurons are activated by physical stimuli impinging on them, and sends signals that inform the central nervous system of the state of the body and the external environment. Motor neurons, situated either in the central nervous system or in peripheral ganglia, connect the nervous system to muscles or other effector organs. Central neurons, which in vertebrates greatly outnumber the other types, make all of their input and output connections with other neurons. The interactions of all these types of neurons form neural circuits that generate an organism's perception of the world and determine its behavior. Along with neurons, the nervous system contains other specialized cells, called glial cells, which provide structural and metabolic support.
The central nervous system (CNS) is the largest part, and includes the brain and spinal cord. The spinal cavity contains the spinal cord, while the head contains the brain. The CNS is enclosed and protected by meninges, a three- layered system of membranes, including a tough, leathery outer layer called the dura mater. The brain is also more... 
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