What is the significance of the human testes being located in scrotal sacs outside the abdomen?

Draw a neat, labelled diagram of a human sperm.

What is the role of the following? (a) Leydig cells (b) Seminiferous tubules

The diagram given below shows a section of the human ovary. (a) Name the process for the release of the part labelled 1. (b) Write the name of the structure marked 2.

A 28-year-old pregnant lady goes to a gynecologist for a check-up. Her doctor explains that there is normal growth of the foetus and the placenta is functioning well. (a) Mention one function of the placenta. (b) What connects the placenta to the foetus?

Mention any two functions of the human foetal placenta.

Read the explanations given below and name the structures: (a) The canal through which the testes descend down into the scrotum just before the birth of a male baby. (b) The part of the brain that regulates the peristaltic movement of the alimentary canal. (c) A structure that collects the soundwaves and conducts them through the external auditory canal. (d) The point of attachment of two chromatids of a chromosome. (e) Regulation of the opening and closing of stomata.

Name the following: (a) The fully developed part of the ovary containing a mature ovum. (b) A waxy layer on the upper epidermis of leaves meant to reduce Transpiration. (c) The ear ossicle which opens into the oval window of Cochlea. (d) The physiological process which is the starting point of all food chains. (e) An insect which is a classic example of natural selection due to industrial melanism.

Match the items in Column I with those in Column II: Column I Column II Leydig cells Lack of thyroxine in children Stoma 12 pairs Ova Testosterone Cranial nerve Diffusion of respiratory gases Cretinism Haploid cells 31 pairs Diploid cells

Arrange the terms in each group in the correct order. Write them in a logical sequence beginning with the term that is underlined. (a) Palisade cells, Cuticle, Upper epidermis, Spongy cells. (b) Hepatic portal vein, Stomach, Hepatic vein, Liver. (c) Cyton, Dendrites, Synaptic cleft, Axon endings. (d) Insulin release, High blood sugar, Lowers blood sugar, Stimulates glucose uptake from blood. (e) Sperm duct, Seminiferous tubule, Epididymis, Efferent ducts.

Assertion (A): Seminal vesicles pour an alkaline secretion into the semen as it passes through the ureter. Reason (R): The female vagina is acidic and needs to be neutralized for sperm survival. (a) A is True and R is False (b) A is False and R is True (c) Both A and R are True (d) Both A and R are False

Name the following: (a) Unicellular outgrowths of the epidermis of roots. (b) The defect of the eye in which some parts of an object are focused while other parts appear blurred. (c) The tropic movement in response to chemicals. (d) The main nitrogenous waste in the human body. (e) The attachment of the fertilized ovum to the wall of the uterus.

Given below is the diagram of a human sperm. Read the information below the diagram and fill in the blanks: Living organisms reproduce to form new individuals of their own kind. This is essential for the survival and continuation of species. Human sperms are microscopic structures that carry genetic material. The head of the sperm has a cap like organelle called (a) ............... (Lysosome / Acrosome) which produces an enzyme (b) ............... (Hyaluronidase / Amylase) that dissolves the outer layer of the ovum to facilitate fertilisation. The nucleus of the sperm has (c) ............... (23 / 46) chromosomes. The middle piece has (d) ............... (Chloroplast / Mitochondria) to provide energy for the motility of the sperm. (e) ............... (Semen / Hymen) is a mixture of sperms and the fluids produced by the male accessory glands.