Science exam

Characteristics of living things

Made of cells, use energy, grow, respond to environment, reproduce, and come from pre-existing cells.

Cell membrane

Controls what enters and leaves the cell.

Cell wall

Rigid outer layer in plant cells for support and protection.

Centrioles

Help organize spindle fibres during cell division.

Chloroplast

Site of photosynthesis in plant cells.

Chromosome

Coiled DNA carrying genetic information.

Cytoplasm

Jelly-like fluid where organelles are suspended.

DNA

Molecule that stores genetic instructions.

Nucleus

Control centre of the cell containing DNA.

Mitochondria

Produces energy through cellular respiration.

Interphase

Cell grows and copies DNA.

Prophase

Chromosomes condense; nuclear membrane breaks down.

Metaphase

Chromosomes line up in the middle of the cell.

Anaphase

Sister chromatids separate to opposite sides.

Telophase

Nuclear membranes reform around chromosomes.

Cytokinesis

Cytoplasm divides into two daughter cells.

Importance of cell division

Needed for growth, repair, and reproduction.

Binary Fission

Asexual reproduction where one cell splits into two equal cells.

Budding

Asexual reproduction where a new organism grows off the parent.

Fragmentation

Asexual reproduction where a piece grows into a new organism.

Sporulation

Asexual reproduction using spores.

Vegetative Reproduction

Asexual reproduction in plants using stems, roots, or leaves.

Sexual vs asexual reproduction

Sexual: two parents, genetic variation. Asexual: one parent, identical offspring.

Interphase I

DNA is copied before meiosis.

Prophase I

Homologous chromosomes pair; crossing over occurs.

Metaphase I

Homologous pairs line up in the middle.

Anaphase I

Homologous chromosomes separate.

Telophase I

Two haploid cells form.

Prophase II

Spindle fibres form again.

Metaphase II

Chromosomes line up in the middle.

Anaphase II

Sister chromatids separate.

Telophase II

Four haploid cells form.

Crossing Over

Exchange of DNA between homologous chromosomes; increases variation.

Advantages of asexual reproduction

Fast, one parent, many offspring.

Disadvantages of asexual reproduction

No genetic variation.

Advantages of sexual reproduction

Genetic diversity.

Disadvantages of sexual reproduction

Slow, requires two parents.

Fertilization

Joining of sperm and egg.

Zygote

First cell formed after fertilization.

Embryo

Early developing organism after cell division begins.

Fetus

Later stage of development with formed organs.

Female reproductive system

Ovaries, fallopian tubes, uterus, cervix, vagina.

Male reproductive system

Testes, epididymis, vas deferens, prostate, urethra, penis, scrotum.

Anaphase

Chromatids separate and move to opposite poles.

Asexual Reproduction

One parent produces identical offspring.

Binary Fission

One cell splits into two identical cells.

Biology

Study of living things.

Body Cell

Any non-sex cell.

Budding

New organism grows from parent.

Cell

Basic unit of life.

Cell Cycle

Stages a cell goes through to divide.

Cell Membrane

Controls movement in and out of the cell.

Cell Theory

All living things are made of cells; cells come from other cells.

Cell Wall

Rigid support layer in plants.

Centrioles

Help with cell division.

Centromere

Point where chromatids are attached.

Cervix

Lower part of uterus opening into vagina.

Chloroplast

Performs photosynthesis.

Chromosome

DNA structure carrying genes.

Compound Microscope

Tool used to magnify small objects.

Crossing Over

Exchange of DNA during meiosis.

Cytokinesis

Cytoplasm divides.

Cytoplasm

Jelly-like interior of cell.

Daughter Cell

Cell produced after division.

Deoxyribonucleic acid

Full name for DNA.

Diploid

Two sets of chromosomes (2n).

Egg

Female gamete.

Embryo

Early development stage.

Epididymis

Stores and matures sperm.

Estrogen

Female hormone.

Fallopian Tubes

Site of fertilization.

Fertilization

Sperm and egg join.

Fragmentation

Organism regrows from a piece.

Gamete

Sex cell with half the chromosomes.

Germinal Cell

Cell that becomes gametes.

Gonads

Organs that produce gametes.

Haploid

One set of chromosomes (n).

Homologous Chromosomes

Chromosome pairs with same genes.

Interphase

Cell grows and copies DNA.

Metaphase

Chromosomes line up in the middle.

Mitosis

Division producing two identical cells.

Mutation

Change in DNA.

Nucleus

Contains DNA.

Organelle

Specialized cell structure.

Ovaries

Produce eggs and hormones.

Penis

Male reproductive organ.

Progesterone

Hormone preparing uterus for pregnancy.

Prophase

Chromosomes condense.

Prostate

Produces semen fluid.

Regeneration

Regrowing lost body parts.

Reproduction

Producing new organisms.

Runner

Horizontal stem forming new plants.

Scrotum

Holds testes.

Seed

Plant embryo with food supply.

Selectively Permeable

Allows some substances through.

Sex Cell

Gamete.

Sexual Reproduction

Two parents produce varied offspring.

Sperm

Male gamete.

Spindle Fibres

Move chromosomes during division.

Spore

Reproductive cell in fungi/plants.