Biology Unit Test

Dna contains stretches of genes, What do genes make?

proteins

2 organ systems in plants

-root system
-shoot system

What does the root system do?

takes in water and minerals from the soil to transport into the hoot system

What does the shoot system do?

organs which support the plant, perform photosynthesis and transport sap.

osmosis/diffusion

movement of water from an area of high concentration to an area of low concentration.

-Diffusion can occur in any mixture, including one that includes a semipermeable membrane.

-while osmosis always occurs across a semipermeable membrane.

What are the 4 plant organs?

➪𝙇𝙚𝙖𝙛 (performs photosynthesis & provides food)
➪ 𝙎𝙩𝙚𝙢 (supports the plant and transports food and water)
➪𝙧𝙤𝙤𝙩 (collects water and anchors the plant)
➪𝙛𝙡𝙤𝙬𝙚𝙧 (involved in reproduction - found in many but not all plants)

Specialized cell

a cell that performs a specific function in a multi-cellular
organism

𝗠𝗲𝗿𝗶𝘀𝘁𝗲𝗺𝗮𝘁𝗶𝗰 𝗰𝗲𝗹𝗹

an unspecialized plant cell that gives rise to a specific specialized cell

apical meristems

Produces primary tissue (found at the tips of roots and shoots)

lateral meristems

produces secondary tissues that increase the width of roots and stems

3 major types of tissues found in a plants body made from meristematic cells

1. 𝗗𝗲𝗿𝗺𝗮𝗹 𝘁𝗶𝘀𝘀𝘂𝗲 ⇨ outermost of the plants organs
2. 𝗚𝗿𝗼𝘂𝗻𝗱 𝘁𝗶𝘀𝘀𝘂𝗲 ⇨ has cells that perform photosynthesis and cells that support the plants body
3. 𝗩𝗮𝘀𝗰𝘂𝗹𝗮𝗿 𝗧𝗶𝘀𝘀𝘂𝗲 ⇨ helps provide physical support and transports nutrients and water

Where do meristematic cells exist?

-terminal bud
-lateral bud
-root tips
(that's why they can grow upward, outward, downward)

fibrous roots

provide the plant with a large surface area over where water can be taken up from just under the surface of the soil,
-Spread out horizontally near the surface of the soil;
-stabilize the soil and protect it from erosion and landslides

Taproot

one main root that grows larger and thicker than the rest
-allows the plant to reach far underground for water

transpiration

gas exchange process, where carbon dioxde comes in through these pores and oxygen and water vapour
leave the plant.

word/chemical equation for photosynthesis (chloroplasts)

carbon dioxide + water + light energy → sugar + oxygen
6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂

word/chemical equation for photosynthesis (cellular respiration)

oxygen + sugar → carbon dioxide + water + energy
6O₂ + C₆H₁₂O₆ → 6CO₂ + 6H₂O + energy

Stomata

-Pores in the leaf that are opened and closed by guard cells to help with the exchange of gases between the leaf and the outside environment.

Guard Cells

pairs of epidermal cells scattered across the lower edge of the leaf to𝗮𝗶𝗱 𝗶𝗻 𝘁𝗵𝗲 𝗲𝘅𝗰𝗵𝗮𝗻𝗴𝗲 𝗼𝗳 𝗴𝗮𝘀𝗲𝘀 𝗯𝗲𝘁𝘄𝗲𝗲𝗻 𝘁𝗵𝗲 𝗹𝗲𝗮𝗳 𝗮𝗻𝗱 𝘁𝗵𝗲 𝗼𝘂𝘁𝘀𝗶𝗱𝗲 environment by regulating the opening and closure of stomatal pores.

xylem and phloem function

2 types of vascular tissue
-𝘅𝘆𝗹𝗲𝗺 distributes water and dissolved minerals upward through the plant, from the roots to the leaves.
-𝗽𝗵𝗹𝗼𝗲𝗺 carries sugars downward from the leaves to the roots.

4 major types of animal tissues

𝗖𝗼𝗻𝗻𝗲𝗰𝘁𝗶𝘃𝗲 - bone, cartilage, fat, blood, and lymphatic tissue.
𝗘𝗽𝗶𝘁𝗵𝗲𝗹𝗶𝗮𝗹 - outer layer of skin (epidermis), lining of intestines, respiratory tract, and abdominal cavity, sweat glands.
𝗡𝗲𝗿𝘃𝗼𝘂𝘀 - Brain, Spinal Cord, and nerves
𝗠𝘂𝘀𝗰𝘂𝗹𝗮𝗿 - cardiac, smooth, and skeletal.

What is a stem cell?

an unspecialized cell that has the potential to either remain a stem cell or become another type of cell with a more specialized function.

Cell

the smallest unit that can perform the functions of life

Tissue

A group of similar cells that perform the same function.

Organ

a combination of several types of tissues working together to perform a specific function.

Organ system

group of organs functioning together

Organism

a group of organ systems functioning together.

Two basic types of cells:

Prokaryotic and Eukaryotic

difference between eukaryotic and prokaryotic cells?

Prokaryotes are always unicellular, while eukaryotes are often multi-celled organisms.

What shape do animal cells have?

round, oval shape

What shape do plant cells have?

rectangular shape

Nucleus

-It controls the cell's activities and is the site of DNA duplication.
-A region with the nucleus, called the nucleolus, makes ribosomes.

cell membrane

-Separates the inside of the cell from the external environment.
-Semi permeable.
-Allows materials to flow into and out of the cell.

Cytoplasm

A jellylike fluid inside the cell . Organelles, and other life-supporting materials, such as sugar and water, all contained by the cell membrane.

Mitochondria

Powerhouse of the cell, Supply cells with energy in the form of ATP.

Ribosomes

Makes proteins

Endoplasmic reticulum:

Connected to the nucleus.
Transports materials made in the cell.
Two types:
-smooth and a plasma in particular ( lipid synthesis ).
-rough endoplasmic reticulum ( has ribosomes attached to it ).

Vesicles

transports and stores materials inside the cell.

Golgi body

sorts and packages proteins and other molecules for transport out of the cell.

Cytoskeleton

Provides a framework for the cell helping it maintain its structure.
- Is involved in an organelle movement.

Lysosomes

Only in animal cells.
- Digest and breakdown nutrients.
- Breakdown old and damaged cell organelles.

Centrosomes

-The major microtubule organizing center of an animal cell.
Animal cells contain centrioles ( within the centrosome ) which are used during cell division.:

Vacuole

A sac inside a cell that acts as a storage area
Contain water and other materials.
Used to store and transport small molecules.
- Plant cells: one large vacuole.
- Animal cells: several smaller vacuoles.

cell wall

-Only found in plants.
-Support the cell.
-Located just outside the cell membrane.

Chloroplasts

-only found in Plant cells
-Trap energy from the sun to produce sugar through photosynthesis

Difference between plant and animal cells

plant cells: chloroplasts, cell walls, and plastids.
animal cells: centrosome, lysosomes

cell theory

1. All living organisms are composed of one or more cells.
2. The cell is the basic unit of structure and organization in organisms.
3. Cells arise from pre-existing cells.

Why do cells divide?

growth, repair, reproduction

Cytokinesis

when the cytoplasm is divided into 2 cells.

Telophase

Chromosomes de-condense
-chromosomes are at the poles of the cell
-the nuclear membrane reappears
-chromosomes begin to unpack into chromatin

Anaphase

-Two identical chromatids split apart
-spindle fibers contract & chromosomes are pulled into opposite poles of the cell

cytokenisis in animals

cell membrane pinches in creating contractile ring in the middle which helps cleave the cell

Cytokenesis in plants

new cell wall forms between the new cells. (cell plate forms)

Chromatid

Each half of the chromosome

when do Chromatids duplicate

S phase

Chromatids after duplication

2 sister chromatids (held at the centromere) called a chromosome

Prophase

Cell begins process of division
-chromosomes condense
-nuclear membrane disappears
-spindle starts to form, growing out of the centrosomes

Why do cells divide?

growth, repair, reproduction

Metaphase

chromosomes line up in the middle of the cell "equator"
-chromosomes are attached to the spindle fibers by their centromere

Mitosis

cycle of the division of the nucleus

What phase do chromosomes duplicate?

S phase (Interphase)

G1 phase

period of cell growth before the DNA is duplicated

S phase

DNA is duplicated (chromosomes are duplicated too)

G2 phase

Period after DNA is duplicated (ends in parent cell)

Interphase

period of the cell cycle between cell divisions (begins in daughter cells)

what are poles

centrioles

Anaphase

Metaphase

Prophase

Telophase

DNA

it's genetic information found in the nucleus of each cell.
Is passed down from parent to child in the form of chromosomes

What does DNA do?

provides directions to repair, construct, and operate the different parts of a cell.

Stores genetic information and codes for protein

DNA looks like a ladder twisted into a shape known as a...

Double helix

The sides of DNA (backbone) is made of...

sugar and phosphate molecules

The middle of DNA is made of...

nucleotide bases (attached to the sugar/phosphate)

The 4 nucleotide bases:

Adenine (A) + (T)
Thymine (T) + (A)
Cytosine (C) + (G)
Guanine (G) + (C)

What does adenine (A) always pair with in DNA?

Thymine (T)

What does guanine (G) always pair with in DNA?

Cytosine (C)

Mutation

a random error in gene replication that leads to a change

Mutagen

substance/ factor that causes a mutation in DNA.

Chromosomes

threadlike structures made of DNA molecules that contain the genes

Where are chromosomes found?

nucleus of a cell

How many chromosomes do humans have?

46 (23 pairs)

male karyotype

XY

female karyotype

XX

digestive system

-breaks down food both mechanically and chemically in order to release nutrient molecules that the body's cells can absorb and use.
-It also removes solid waste from the body.

2 types of digestion

mechanical - physical breakdown of food (e.g teeth)
chemical - addition of special substances that breakdown (e.g stomach acid)

4 stages of digestive process

1. Ingestion: voluntary process (eating)
2. Digestion: breakdown of food into smallest nutrients
3. Absorption: bringing nutrients into the bloodstream
4. Elimination: elimination of indigestible food (feces)

How is the human body organized?

cells 🠮 tissues 🠮 organs 🠮 organ systems

The Mouth

mouth starts process of breaking down food (mechanical)

Teeth

-Tear and rip apart
-Mechanical/physical digestion

Tongue

Muscular organ that helps move food

Saliva

-Moisten food and breaks down food
-Chemical digestion (the enzymes found in saliva)

Esophagus

passes food and liquid from your mouth to your stomach.
-made of smooth muscle
(peristalsis)

Peristalsis

muscle contractions that help move food down to your stomach and through the small intestine.

stomach

where food is held (mechanical digestion)

hydrochloric acid (HCl)

stomach acid to chemically digest food

small intestine

➢absorption of nutrients (chemical digestion)
➢Extends from the stomach to the large intestines
➢Most digestion occurs

Villi & Microvilli

increase surface area for absorption
-Fingerlike projections into the small intestines

large intestine

-Absorption of water & salt
-elimination of undigested food occurs here