The biologists concluded that the shrimps in the open had a higher genetic diversity than in the cave. Explain how the data in Figure 4 support this conclusion. More alleles of each gene/shrimps in open have all the alleles The percentage of shrimps with allele L in the cave is different from the percentage of shrimps with allele L in the open. Use your knowledge of the founder effect to suggest a reason for this difference. A small number of shrimps were /went into the cave; All/high proportion of shrimps had allele L; Cave population descended from these/these reproduce The biologists who studied these shrimps wanted to know if the shrimps living in the cave were the same species as those living in the open. They used breeding experiments to investigate this. Describe how the biologists should carry out these breeding experiments. Cross shrimps from two sites/watch courtship; Breed young together/observe mating; Allow 1 mark for any method of improving quality of results e.g. carry out reciprocal crosses/large number of crosses/isolate beforehand The results of breeding experiments would help the biologists to decide whether the shrimps were the same species. Explain how. If same species the shrimps would breed, producing fertile young/courtship species specific Give one feature of starch and explain how this feature enables it to act as a storage substance. Helical /spiral/coiled; Compact / description e.g. packed’; Insoluble; Prevents osmosis/uptake ‘tightly of water / does not affect water potential / (starch) does not leave cell; Large molecule / long chain; Does not leave cell The diagram shows part of a cellulose molecule. Name part A. Glucose β/beta Name bond B. Glycosidic The structure of cellulose is related to its role in plant cell walls. Explain how. Long/straight/unbranched chains (of glucose); (Joined by) hydrogen bonds; Form (micro)fibrils/(macro)fibrils; Provide rigidity/strength/support
The biologists concluded that the shrimps in the open had a higher genetic diversity than in the cave. Explain how the data in Figure 4 support this conclusion. More alleles of each gene/shrimps in open have all the alleles The percentage of shrimps with allele L in the cave is different from the percentage of shrimps with allele L in the open. Use your knowledge of the founder effect to suggest a reason for this difference. A small number of shrimps were /went into the cave; All/high proportion of shrimps had allele L; Cave population descended from these/these reproduce The biologists who studied these shrimps wanted to know if the shrimps living in the cave were the same species as those living in the open. They used breeding experiments to investigate this. Describe how the biologists should carry out these breeding experiments. Cross shrimps from two sites/watch courtship; Breed young together/observe mating; Allow 1 mark for any method of improving quality of results e.g. carry out reciprocal crosses/large number of crosses/isolate beforehand The results of breeding experiments would help the biologists to decide whether the shrimps were the same species. Explain how. If same species the shrimps would breed, producing fertile young/courtship species specific Give one feature of starch and explain how this feature enables it to act as a storage substance. Helical /spiral/coiled; Compact / description e.g. ‘tightly packed’; Insoluble; Prevents osmosis/uptake of water / does not affect water potential / (starch) does not leave cell; Large molecule / long chain; Does not leave cell The diagram shows part of a cellulose molecule. Name part A. β/beta Glucose Name bond B. Glycosidic The structure of cellulose is related to its role in plant cell walls. Explain how. Long/straight/unbranched chains (of glucose); (Joined by) hydrogen bonds; Form (micro)fibrils/(macro)fibrils; Provide rigidity/strength/support