Sem 1 Science Exam Year 10

What is a Chromosome?

A thread-like structure inside cells that carries genetic information (DNA) from parents to offspring.

What is an Autosome?

Any Chromosome that isn’t a sex chromosome

What is a Sex Chromosome?

A chromosome that determines an individual’s sex.

How are Male and Female Sex chromosomes expressed?

Male: XY

Female: XX

What is another name for Sex Cells?

Gametes

What is a Chromatid?

One of the two identical copies of a chromosome that are joined together before a cell divides.

What is Zygote?

A call that is formed when a sperm cell fuses with an eggs cell

What is a Nucleotide?

The basic building block of DNA and RNA, consisting of a sugar, a phosphate group, and a nitrogenous base.

The type of groups present in a nucleotide?

Phosphate

The type of glucose used in nucleotides?

Deoxyribose Sugar

All Nitrogenous bases

Thymine, Guanine, Adenine, Cytosine

All base pairs

Adenine → Thymine

Guanie → Cytosine

What does DNA stand for and what does it do?

Deoxyribonucleic Acid. It stores and carries the genetic instructions that tell living things how to grow, develop, function, and reproduce.

What does RNA stand for and what does it do?

Ribonucleic Acid and it is a molecule that helps carry genetic information and is involved in making proteins in cells.

What is Cytoplasm?

The jelly-like substance inside a cell that surrounds and supports the organelles.

What is a gene?

A section of DNA that contains the instructions for a specific trait or function in an organism.

What is an Allele?

A different version of a gene, you inherit one from each parent.

What is Asexual Reproduction?

From 1 parent. All offspring are genetically identical to each other and parent.

What is a recessive characteristic?

A trait that is only expressed when an individual inherits two recessive alleles, one from each parent.

What is a dominant characteristic?

A trait that is expressed when an individual has at least one dominant allele for that trait.

What are Homozygous alleles and how are they expressed in punnet square form?

Two alleles that are identical. Expressed as: BB or bb

What are Heterozygous alleles and how are they expressed in punnet square form?

Two alleles that are different. Expressed as: Bb

What are Punnett squares used for?

A way to represent the probability of characteristics of a certain gene

What is Genotype?

The specific set of genes or versions of genes present in the alleles.

What is a Phenotype?

The observable characteristics or traits of an organism that result from its genotype and environment.

What is Intermediate Inheritance?

When neither allele is completely dominant, so the offspring show a blended or intermediate trait.

What is Co-Dominant Inheritance?

When both alleles are fully expressed at the same time in a heterozygous organism. Both equally expressed.

What is F.O.I.L?

First, Outside, Inside, Last

Two types of Cell Division

Mitosis and Meiosis

What is Mitosis used for?

Growth + Repair

What is Meiosis used for?

To produce sex cells like sperm and egg cells.

Describe the process of Mitosis

Before division, the DNA replicates leading to 46 pairs of chromosomes (92 chromosomes), then one of each chromosome is pulled to either end of the cell and cell the cell divides, creating 2 daughter cells. Each daughter cell is identical to the original cell.

Describe the process of Meiosis

Before division, the DNA replicates, leading to 46 pairs of chromosomes (92 chromosomes). One of each chromosome is pulled to either end of the cell and the cell divides, creating 2 daughter cells. One chromosome for each pair is pulled to either end of the cell and the cell divides gain, creating a total of 4 daughter cells. The daughter cells have half as many chromosomes as the original cell.