Genetics

Chromosomes

Thread-like structures located inside the nucleus that carry DNA and are tightly wound strands of DNA.

Where are chromosomes found?

Nucleus.

What are chromosomes made up of?

DNA and proteins.

What does DNA stand for?

Deoxyribonucleic acid.

What is the shape of DNA called?

Double helix.

What is the main function of DNA?

To control the production of proteins as dictated by the DNA code.

Name the four Nitrogen Bases of DNA.

Adenine, Thymine, Cytosine, Guanine.

What pairs with Guanine?

Cytosine.

What pairs with Adenine?

Thymine.

Complete the DNA replication code: G C T A A G C A

C G A T T C G T.

How many chromosomes are there in the nucleus?

46.

What is the process of making new body cells?

Mitosis.

How many body cells are produced during each process of mitosis?

2 identical daughter cells.

How many chromosomes do human sex cells have?

23 chromosomes.

How many gametes are formed during the process of meiosis?

4 gametes.

Why must sex cells have 23 chromosomes?

Each parent contributes 23 chromosomes.

What is the 23rd pair of chromosomes called?

Sex chromosomes.

What sex chromosomes make up a male?

XY.

What sex chromosomes make up a female?

XX.

What happens during Interphase?

The cell grows and DNA is duplicated.

What occurs during Prophase?

DNA condenses and forms visible chromosomes, the nucleus dissolves, and spindle fibers form.

What happens during Metaphase?

Chromosomes line up in the middle of the cell, attached to spindle fibers.

What occurs during Anaphase?

Chromosomes are pulled toward opposite sides of the cell by spindle fibers.

What happens during Telophase?

The nuclear membrane reforms around the chromosomes and they unwind back into chromatin.

What is Cytokinesis?

The process where the cytoplasm divides resulting in two daughter cells.

What is a change in DNA or on the chromosome known as?

A mutation.

Are all mutations bad?

No, some mutations can be advantageous or neutral.

How is sexual reproduction different from asexual reproduction?

Sexual reproduction requires a male and female and produces variation; asexual reproduction produces genetically identical clones.

What does asexual reproduction produce?

Offspring that are genetically identical to the parent organism.

What type of reproduction is Mitosis an example of?

Asexual reproduction.

What is Evolution?

The process by which living organisms are thought to have developed and changed from earlier forms over the history of earth.

What is a major difference between natural selection and selective breeding?

Natural selection is influenced by nature; selective breeding is influenced by human choices.

What causes natural selection?

Variation, Competition, Inheritance, Time, Adaptation.

What did Darwin study about the finches?

He studied their beak variations based on food sources available.

What are the different pieces of evidence that support the Theory of Evolution by Natural Selection?

Fossil records, Homologous structures, Vestigial structures, Embryology.

Evaluate the relationship between natural selection and evolution.

Natural Selection leads to evolution by allowing individuals with favorable traits to survive and reproduce, leading to species changes over time.