Back to Details Unit Test - Heredity, Inheritance, and Variation Open in Editor

Unit Test - Heredity, Inheritance, and Variation

Grade 7 Science Unit Assessment

            📚 Science
                            🎓 Grade 7
                                        ⏱️ 45 minutes
                    

Learning Objectives

Distinguish between inherited and acquired traits and explain the relationship between DNA, chromosomes, and genes
Define alleles, distinguish dominant from recessive, and explain the difference between genotype and phenotype
Use Punnett squares to predict offspring trait probabilities
Compare sexual and asexual reproduction and explain why genetic variation is important for species survival
Describe how environment and lifestyle can affect gene expression and distinguish heritable mutations from non-heritable changes

1
Unit Test
                            ~45 minutes                        

Question 1

Which statement BEST describes heredity?

The study of how organisms grow, develop, and change over time
The passing of traits from parents to offspring through genes
The process of organisms slowly adjusting to their environment
The way organisms interact with other members of their species

Question 2

A student's mother has naturally red hair, and the student also has naturally red hair. This is BEST explained as:

An acquired trait influenced by the family's environment
An inherited trait determined by genetic information
A coincidence not connected to genetic inheritance
A mutation that occurred during the student's growth

Question 3

A weightlifter builds enormous muscles through years of training. If this weightlifter has children, which outcome is MOST likely?

The children will be born with larger muscles than average
The children inherit the weightlifter's strength directly
Their muscle size depends on their own genes and exercise
The children will not be able to build any muscle mass

Question 4

How many chromosomes are found in a typical human body cell?

23 chromosomes, all inherited from one parent
46 chromosomes, arranged in 23 matched pairs
92 chromosomes that double during cell growth
23 pairs that only appear during cell division

Question 5

Match each term with its correct definition:

Question 6

Arrange the following from SMALLEST to LARGEST:

[Unsupported question type: ordering]

Question 7

What term describes a different version of the same gene?

A chromosome within the cell's nucleus
A specific segment of the DNA molecule
An allele inherited from a parent
A phenotype displayed by an organism

Question 8

An organism shows a recessive phenotype. What must be true about its genotype?

It has one dominant and one recessive allele
It carries at least one copy of the dominant allele
It has two copies of the recessive allele for that gene
Its genotype cannot be determined from the phenotype

Question 9

A brown cat (BB) and a brown cat (Bb) look identical. Why do both cats display the same fur color?

One copy of the dominant allele is enough to show brown
Genotype and phenotype are always identical in mammals
The surrounding environment controls each cat's fur color
All brown cats must carry two copies of the dominant allele

Question 10

Match each genotype to its correct classification:

Question 11

Which of the following are INHERITED traits? (Select ALL that apply)

Natural blood type (A, B, AB, or O)
A scar received from a childhood accident
Ability to roll your tongue
Widow's peak hairline shape
Speaking a foreign language fluently

Select all that apply.

Question 12

Two organisms with different genotypes must always have different phenotypes.

Question 13

When two heterozygous parents (Bb) are crossed, what is the expected genotype ratio of their offspring?

All offspring will be Bb, none are BB or bb
1 BB : 2 Bb : 1 bb out of every four offspring
2 BB : 0 Bb : 2 bb out of every four offspring
0 BB : 4 Bb : 0 bb, every offspring heterozygous

Question 14

In a cross of Bb x Bb where B (black fur) is dominant over b (white fur), what is the expected phenotype ratio?

All four offspring display the black fur phenotype
Half display black fur and half display white fur
Three display black fur and one displays white fur
Each offspring has an unpredictable and random color

Question 15

A homozygous dominant parent (BB) is crossed with a homozygous recessive parent (bb). What percentage of offspring show the dominant phenotype?

0% of offspring display the dominant phenotype at all
25% of offspring display the dominant phenotype
50% of offspring display the dominant phenotype
100% of offspring display the dominant phenotype

Question 16

A father can roll his tongue (Rr) and a mother cannot roll her tongue (rr). What is the probability that their child can roll their tongue?

100%, every child will be a tongue roller
75%, three out of four children will roll
50%, about half may inherit the ability
0%, none of their children will be able to

Question 17

Match each Punnett square cross to its expected phenotype outcome (B = dominant, b = recessive):

Question 18

Put the steps for using a Punnett square to predict offspring in the correct order:

[Unsupported question type: ordering]

Question 19

How does sexual reproduction differ from asexual reproduction?

Sexual reproduction is faster and requires less energy
Asexual reproduction combines genes from two parents
Sexual uses two parents and produces unique offspring
Both types produce genetically identical clone offspring

Question 20

Why does sexual reproduction produce greater genetic variation than asexual reproduction?

Sexual reproduction causes more mutations in DNA
It mixes alleles from two parents into new combinations
Asexual organisms cannot reproduce at fast enough rates
Only sexually reproducing organisms carry alleles in DNA

Question 21

All Cavendish bananas are genetically identical clones. Why does this make the entire crop vulnerable to Panama Disease?

Clones are inherently weaker organisms than non-clones
Bananas cannot reproduce through any sexual processes
No genetic variation means no individual has resistance
Panama Disease specifically targets only cloned organisms

Question 22

Match each method of asexual reproduction with its description:

Question 23

Why is genetic variation important for the survival of a species? (Select ALL that apply)

Some individuals may survive diseases that kill others
It provides raw material for natural selection to act on
It makes every organism in the population genetically identical
It helps species adapt when environments change over time

Select all that apply.

Question 24

Put these events in the correct order to show how genetic variation helps a population survive a new disease:

[Unsupported question type: ordering]

Question 25

When bacteria reproduce by binary fission, the two new cells are genetically different from each other.

Question 26

Which statement BEST describes gene expression?

The total number of genes found in an organism's DNA
How actively a gene produces its protein product
The process of passing genes from parent to offspring
The physical appearance that an organism can display

Question 27

Which situations could produce a DNA change that is passed on to offspring? (Select ALL that apply)

A mutation occurs in an egg cell before fertilization
A mutation happens in a skin cell from too much sunlight
A mutation occurs in a sperm cell before fertilization
A person develops stronger muscles through daily exercise

Select all that apply.

Question 28

PKU is an inherited genetic condition. However, a special diet can reduce its harmful effects. What does this demonstrate?

PKU is caused entirely by dietary choices and not by genes
Environment can influence how inherited genes are expressed
All genetic conditions can be fully cured by changing diet
PKU is not actually a condition caused by genetic factors

Question 29

If an athlete trains for years and develops extremely fast reflexes, their children will inherit those fast reflexes.

Question 30

A(n) ______ is a different version of the same gene.

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