14.2. Sense organs
A subsection of Biology, 0610, through 14. Coordination and response
Listing 10 of 148 questions
The eye is a sense organ. Define the term sense organ. Explain why the eye is described as an organ and not a tissue. shows a section through the eye. A B C D E F G Select letters from to match the part with its function. Write your answers in Table 2.1. Table 2.1 function letter carries impulses to the brain contains light receptors to detect light controls how much light enters the eye refracts light Write down the letter from which shows the position of the blind spot.
0610_w16_qp_31
THEORY
2016
Paper 3, Variant 1
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The eye is a sense organ that responds to light. is a diagram of a section through the human eye. Q W X Y R S T U Table 4.1 describes some of the functions of the parts of the eye. Complete the table by: • naming the parts of the eye • using the letters on to identify the parts of the eye. Table 4.1 function name of part letter on carries impulses to the brain focuses light onto the back of the eye controls the tension of the suspensory ligaments tissue that detects light and colour location of most of the cone cells A pair of muscles in the eye work in opposition to each other to adjust the amount of light entering the pupil. State the term that describes the action of a pair of muscles working in opposition to each other. A different pair of muscles in the eye work in opposition to each other to view objects at different distances from the eye. State the name of the process that allows the eye to view objects at different distances. Explain why the eye cannot easily identify different colours in low levels of light. Some people inherit colour blindness and cannot identify certain colours, even in bright light. The gene responsible for colour vision is located on the X chromosome. There are two alleles for this gene on the X chromosome: • XB – normal colour vision • Xb – colour blindness. People that are heterozygous for colour blindness are called carriers. State the genotype of a heterozygous female carrier. There is no gene for colour vision on the male sex chromosome. State the genotype of a colour-blind male. shows a pedigree diagram for colour blindness. colour vision female carrier female colour-blind female colour vision male carrier male colour-blind male Key: Person 13 in is male. His parents are person 7 and person 8. Use the key to complete by drawing the correct symbol for person 13. Colour blindness is a sex-linked characteristic. Explain why females 4 and 5 are carriers even though their mother is not a carrier.
0610_w18_qp_41
THEORY
2018
Paper 4, Variant 1
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Questions Discovered
148