Cell divison and Growth

What are three structures that distinguish plant cells from animal cells?

Cell wall

plastids

large central vacuole.

What is special about the plant cell wall?

It contains plasmodesmata, which allow communication between plant cells.

What are plastids?

Organelles found in plant cells that perform functions such as photosynthesis and pigment or food storage.

What are three types of plastids?

Chloroplasts

chromoplasts

leucoplasts.

What is the large central vacuole?

A large storage organelle that contains cell sap and helps maintain turgor pressure.

What is the tonoplast?

The membrane surrounding the central vacuole.

How does a tiny seed grow into a massive tree?

Through cell division and cell growth, which produce new plant tissue.

Where does new plant tissue come from?

From meristems, regions of actively dividing cells.

What is an annual plant?

A plant that completes its life cycle in one growing season/year.

What is a biennial plant?

A plant that typically completes its life cycle over two growing seasons/years.

What is a perennial plant?

A plant that lives for more than two years.

What is a woody perennial?

A perennial plant that develops woody stems and can continue growing for many years.

What is a herbaceous perennial?

A perennial plant with soft, non-woody stems that often die back to the ground during part of the year.

What are the Northern and Southern Hemispheres?

The Northern Hemisphere is the half of Earth north of the equator,

while the Southern Hemisphere is south of the equator.

Why are the seasons opposite in the Northern and Southern Hemispheres?

Because Earth's axis is tilted, so the two hemispheres receive different amounts of sunlight at different times of the year

What is cell division?

The process where a cell reproduces and divides into new cells.

Whats the process where a cell reproduces and divides into new cells.

They are divided between two daughter cells.

What are the two main stages of cell division?

Mitosis and cytokinesis.

Where does cell division mostly occur in plants?

In apical meristems.

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What is mitosis?

The process where the nucleus divides.

What is interphase?

The preparation stage before mitosis when the cell grows, performs normal functions, and copies its DNA.

When is DNA copied?

During interphase, specifically the S phase.

What happens during prophase?

Chromosomes condense and become visible, and the cell prepares for chromosome separation.

What happens during metaphase?

Chromosomes line up in the middle of the cell.

What happens during anaphase?

Sister chromatids are pulled apart toward opposite sides of the cell.

What happens during telophase?

New nuclei form around the separated chromosomes.

What happens during cytokinesis?

The cytoplasm divides, producing two separate daughter cells.

What is the order of the stages?

Interphase → Prophase → Metaphase → Anaphase → Telophase → Cytokinesis

What is the end result of mitosis and cytokinesis?

Two genetically identical daughter cells with the same chromosome number as the original cell.

Why is mitosis important?

It allows organisms to grow, replace damaged cells, and produce new cells.

How does mitosis help a plant grow?

It produces new cells that can grow and develop into different plant tissues

What is a plant-specific feature of cytokinesis?

Cell plate formation.

Where does mitosis occur in plants?

Mainly in special regions called meristems.

Why do scientists use root tips to study mitosis?

Root tips contain apical meristems, where cells are constantly dividing, so many cells can be observed in different stages of mitosis.

What is cytokinesis?

The division of the cytoplasm into two daughter cells.

What happens during plant cytokinesis?

A cell plate forms in the middle of the cell.

What does the cell plate eventually become?

It becomes the precursor to the new cell wall between the two daughter cells.

Why is a cell plate necessary in plants?

Plant cells have a rigid cell wall, so they cannot simply pinch in half like animal cells.

What is vegetative propagation?

A form of asexual reproduction where new plants grow from parts of an existing plant instead of from seeds.

What are root suckers?

Shoots that grow from a plant's roots and can develop into new plants

How does black locust reproduce vegetatively?

Through root suckers.

What is an example of a plant that uses vegetative propagation?

American chestnut.

What is a clonal organism?

An organism made up of genetically identical individuals that originated from one original organism.

What is Pando?

A famous clonal organism made up of genetically connected aspen trees.

What is primary growth?

Growth that makes a plant longer and taller

Where does primary growth occur?

At the tips of roots and shoots.

What type of meristem causes primary growth?

Apical meristems.

What does an apical meristem do?

It produces new cells that allow the roots and shoots to grow longer.

What is secondary growth?

Growth that makes stems and roots wider/thicker.

Where does secondary growth occur?

Along the sides of stems and roots.

What type of meristems cause secondary growth?

Lateral meristems.

What are the two types of lateral meristems?

Vascular cambium and cork cambium.

What does secondary growth allow a plant to do?

It allows stems and roots to increase in diameter.

What are woody perennials?

Plants that live for many years and have woody stems.

Why can some woody perennials keep growing?

Their meristems continue producing new cells, allowing continued growth.

What is a meristem?

An undifferentiated tissue made of cells that can divide and later develop into specialized plant tissues

What is the main function of meristems?

They are regions where mitosis actively occurs.

Where are apical meristems located?

At the tips of stems and roots.

What type of growth do apical meristems produce?

Primary growth, which makes the plant longer or taller.

Where are lateral meristems located?

Along the sides of stems and roots.

What type of growth do lateral meristems produce?

Secondary growth, which makes stems and roots wider.

Why can pruning sometimes make a plant grow wider?

Removing the main growing tip can reduce apical dominance, allowing side buds to grow and produce more branches.

What is apical dominance?

The tendency of the main shoot to suppress the growth of side shoots.