Chromosome number variation loss-of-function allele physiological trait discovery-based science genetic cross a. human genome project b. down syndrome c. model organism d. pku e. lactose metabolism

Chromosome number variation: B. Down syndrome

Loss-of-function allele  : D. PKU

Physiological trait : E. Lactose metabolism

Discovery-based science : A. Human Genome Project

Genetic cross: C. Model organism

Explanation:

Down syndrome is a condition in which there is an extra copy of the chromosome number 21. Hence, it is a chromosome number variation.

Physiological traits refers to any function of a body. Hence, it matches with lactose metabolism.

Human Genome Project was a project under which the whole genome of the humans were sequenced. Hence, it is a discovery based science.

A genetic cross is made between model organisms to test for the offsprings that would be produced from a cross. Hence, genetic cross and model organism math with each other.

answer: tributaries flow into rivers.

wetland is a biome that develops when the water gets accumulated in a land exhibiting a huge depression. these form either seasonally or permanently. the water in the wetland comes from rivers, lakes, ocean, flood, rain or other sources. the wetlands includes mangroves, marshes and peatland.

tributaries flow into the rivers develops a wetland because such water will get deposited in the depression and will restrict the original flow of tributary water. hence, water with low drainage current combines with the river water.

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