Inheritance and Expression of Traits

[Objective 1] Which option describes genes?

• Any sequence of DNA that is above a certain size.

• A single, whole strand of DNA molecule.

• Any part of a DNA molecule.

• A sequence of DNA that codes for something.

[Objective 1] Read the statement.

_____ are long chains of DNA. They also contain some stabilizing _____ called histones.

Which option correctly completes this statement?

• Chromosomes, amino acids

• Genes, amino acids

• Genes, proteins

• Chromosomes, proteins

[Objective 1] Study the image.

The image shows how DNA is packed.

Which label in the image shows histones

• 4

• 3

• 2

• 1

Tags

NGSS.HS-LS1-1

[Objective 1] Read the statement.

All of DNA directly codes to make proteins.

Is this statement true or false?

• True. 100% of DNA needs to be expressed in order for an organism to function.

• False. DNA codes to make carbohydrates, not proteins.

• False. Only a small percentage of DNA directly codes for proteins.

• True. 100% of DNA consists of genes.

Tags

NGSS.HS-LS1-1

[Objective 1] Read the statement.

A cell is in its life cycle. Currently, it is not in the process of cell division.

Which option describes the shape of its chromosomes?

• Dense, coiled into spheres.

• Loose, noodle-like.

• Loose, stretched out in a long single-strand spiral.

• Dense, coiled into X shapes.

[Objective 1] Which option(s) correctly describes chromosomes?

• Most human cells have two copies of each chromosome - one from each parent.

• Chromosomes consist of tightly coiled DNA wrapped around proteins called histones.

• Chromosome pairs contain completely different genes.

• Each chromosome has one gene.

Tags

NGSS.HS-LS3-1

[Objective 1] Which molecule stores the instructions for various traits in an organism?

• Protein.

• Deoxyribonucleic acid.

• Lipid.

• Carbohydrate.

Tags

NGSS.HS-LS1-1

NGSS.HS-LS3-1

[Objective 2] Read the statement.

During sexual reproduction, the sperm and the _____ join. This process is called _____.

Which option correctly completes this sentence?

• ovary, fertilization

• ovary, crossing over

• egg, crossing over

• egg, fertilization

Tags

NGSS.MS-LS3-2

[Objective 2] Read the statement.

Each person inherits 23 chromosomes from their mother and 23 chromosomes from their father. Thus, a person has two copies of each chromosome. The two copies are called homologous pairs. Crossing over is a process that happens between homologous pairs of chromosomes.

Which option correctly summarizes crossing over?

• During fertilization, the sperm contributes only a single chromosome. The remaining chromosomes come from the egg.

• During fertilization, the sperm and the egg join to form a single cell with 23 pairs of chromosomes.

• During meiosis, homologous chromosomes split to form sperm or eggs. Each sperm or egg has 46 chromosomes

• During meiosis, homologous chromosomes exchange sections of DNA. This introduces variation and makes each chromosome copy unique.

[Objective 2] In sexual reproduction, why is fertilization necessary to produce an organism?

• Fertilization is needed so that the egg cell can obtain nutrients from the sperm cell. Without these nutrients, an organism cannot develop.

• Fertilization allows an organism to reproduce asexually, making identical clones of itself.

• Fertilization allows an organism to receive a complete set of chromosomes - one set from each parent.

• Fertilization is needed to make the cell bigger. A bigger cell leads to the development of an organism.